Q: I've got a bright green grass that is shooting up through my lawn. I think you wrote about this once, but I can't remember what it's called or what to do about it.

A: You're probably talking about nutsedge, a.k.a. nutgrass. It's technically not a grass, but it looks like one, only it grows faster than regular turfgrass and sticks up like a skinny yellow/green weed. (A distinguishing feature is the triangular stem.)

Nutsedge is botanically similar enough to lawngrass that the usual lawn weed-killers such as Weed-B-Gon don't kill it. It's not an easy weed to control.

If you've got only a few patches, just pull it up. After a rain is best. Try to get the whole plant because if you let any of the little nutlets behind, they'll resprout.

If that's out of the question, three chemical herbicides do a fairly decent job. Unfortunately, the two most effective ones (SedgeHammer and Basagran) aren't readily available to homeowners. So you may need to hire a licensed pro to apply those. Keep in mind that even these aren't 100 percent effective and usually require two or even three applications. Both also may yellow the surrounding lawn and are less effective on well established nutsedge. Basagran (bentazon) is especially rough on perennial ryegrass - typically a main component of home lawns.

The third and most available herbicide is one containing MSMA (monosodium acid methanearsonate). That's in a variety of garden-center junk-grass killers, such as Bayer Advanced's All-in-One Weed Killer for Lawns.

MSMA has the same shortcomings as above, only you can take a crack yourself for less money. Don't overdo it. Stronger is not better. And like SedgeHammer and Basagran, you'll probably need two or more applications.

One other option is brushing the kill-everything herbicide glyphosate (i.e. Roundup) over the tops of the nutsedge. If you don't drip or brush the Roundup onto the lawngrass, you may be able to kill off the taller nutsedge without hurting the lawngrass below. That's not easy. But even if you kill the good grass, at least you can start over - nutgrassless - by reseeding.

I'm personally not a fan of using any herbicide unless absolutely backed up against the wall. Regular mowing at least will keep nutsedge from seeding, and vigilant hand-pulling should reduce if not ultimately eliminate the problem.